Short circuit, something is broken but what?

Hello everyone,

I just fixed some issues with my i3 but facing new ones allready. I was being very very stupid and created a short circuit while trying to measure the voltage but the multimeter was set to ampere. I connected the + and - of the heatbed for like 0,0001 second while it was on and heared a little cripsy sound.

After checking every function of the printer there are two problems:

1. The heatbed wont go off. As soon as i plug in the PS it starts heating. No matter what i tell it to do.

2. The Y motor behaves like it doesnt gets enough current but cranking it up doesnt get me anywhere. It just doesnt do anything and when im lowering the current it starts shaking.

Whats the best move right now? I've no clue what parts ive just destroyed. :-(

You definately fried the MOSFET driving the heatbed. Start there.

Jep, MOSFET even started smoking when i was testing the stepperdrivers.. Thanks for the handout, im going to replace the Ramps and one of the stepperdrivers.

The mosfet on the RAMPS should be easy enough to replace, they are through-hole components.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Yeah but i couldnt find the right mosfet and ordering a new RAMPS cost me less time

Everything is fixed now. Thanks for your help!

Quote
navyblueboss
Yeah but i couldnt find the right mosfet and ordering a new RAMPS cost me less time

For future reference (and it's not a bad idea to just replace at least the bed's MOSFET anyways), this MOSFET is generally recommended as an upgraded replacement as it operates cooler at higher current loads.